Added week 6

week6/ex3.py

@@ -0,0 +1,21 @@
+def main():
+    print('==Exercise 3==')
+    
+    flag=True
+    while flag:
+        a = input("pls input a number:")
+        try: 
+            a = int(a)
+            flag=False
+        except :
+            print("pls input a number!")
+    
+    print(f"Test if the number {a} is even: {True if a%2==0 else False}")
+
+    #我其实挺想直接a%2==0的，不过尊重一下本节课的主题
+    
+    print('==End Of Ex3==')
+    return 0
+
+if __name__ == '__main__':
+    main()